January 24, 2018

Australian Future Sub's Diesel Genset Requirements - PART THREE

The critical issues of providing sufficiently powerful and
reliable diesels for Australian future submarines are complex. Unreliable diesels and generators seem to have been the main weakness of the Collins.Australia enthusiasm for selecting a Japanese submarine in the years up to 2016 relied heavily on an Australian assessment that the KAWASAKI 12V/25/25SB was the best high power submarine diesel available worldwide. The 12V25/25SB has been successfully used on Japanese subs since 2005 (see sidebar). So far I think Naval Group should work through
the MAN Diesel & Turbo SE (which owns SEMT Pielstick diesel builder) grouping
to obtain the 12V/25/25SB diesels under licence. Or perhaps obtaining Kawasaki's newly developed 12V25/31S (to be installed in 29SS, to be laid down in 2018/19 - see TABLE) as this will gradually replace the 12V/25/25SB. This is noting MAN and
Kawasaki are already closely associated on marine diesels.

As outlined in PART TWO diesels (around 1.4MW or less) for smaller European designed submarines are inadequate in power to meet Australian submarine needs. Four more powerful diesels (around 2MW each) are required. This would avoid the need for 6 “euro” diesels (an arrangement which would inefficiently stretch the Australian submarine's length and/or diameter.

On the need for four diesels submarine expert Hans J. Ohff, with much knowledge and many Adelaide and Canberra contacts, commented on Selection of Naval Group Day
(April 26, 2016) that:

"The [Australian future submarine] will be equipped with four diesel alternators to
generate electricity, a >7 megawatt permanent magnet motor and ample battery
storage."

A Kawasaki-MAN effort to introduce Kawasaki diesels for Australian use should preferably avoid major alterations, like an Australia Only turbocharger-supercharger system, due to technical/reliability risk.

Australian submarine diesels will not function in isolation. Other power
train components matter. In that vein it appears that Naval Group has already
selected Jeumont Electric as the official supplier of the generator pack
which includes manufacturing permanent-magnet synchronous motors and the
associated power electronics cabinets. Hence the diesel supplier will need to
work closely with Jeumont Electric on a business and technical level.

3 comments:

Anonymous
said...

Hi Pete

Assuming engine speed of 12V/25/31S is as same as 12V/25/25SB and its torque is simply proportional to cylinder capacity, its electrical output will exceed 2.2MW. So, I expect electrical output is at least 2MW.

According to official report by Japan Ministry of Defense (MoD) in 2009, MTU 16V396SE and SEMT-Pielstick PA4V200SM were excluded from diesels for next generation submarine (=29SS), because output of these diesels was even lower than exsiting diesel (=KASAKI12V25/25SB) and could not satisfy requirements [1].

Why does nonconforming diesels for 29SS become conforming for bigger submarine.

12V25/25S was developed as submarine dedicated diesel from scratch by KHI and is not modified version of general purpose diesel. Development concept of 12V25/25S is small size, high power and quietness for submarine use. 36 of 12V25/25Ss (mechanical output 1985kW) and 22 of 12V25/25SBs (2280kW) are manufactured, and none of them experienced troubles, except ones caused by wrong parts which subcontractor misused at maintainance.

New snorkel generation system using 12V25/31S (modified version of 12V25/25SB, estimated mechanical output is 2827kW) was already developed and its performance was demonstrated 4 years ago. 12V25/31Ss are used for FY2017 submarine.

As KHI already manufactured 52 KASAWAKI/MAN diesels before 12V25/25S, KHI is one of the major submarine diesel manufacturers.

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